Outrigger boom for earthworking vehicles

ABSTRACT

An outrigger boom has an elongated, angular support cradle which can be attached to an earthworking vehicle or its movable earthworking element and a telescoping boom assembly having its inner end pivoted on the inboard end of the cradle so that the boom assembly can be aligned with the cradle and tightly clamped therein when in use to rigidly couple them so a universally adjustable mounting device at the outer end of the boom assembly can attach and orient sensing transducers whereby external references can be utilized for control system reference even though such references are located somewhat remote to the vehicle&#39;&#39;s operating area.

11 3,736,937 .lune 5, 1973 United States Patent 1 Easterling 3,495,6632/1970 Scholl et al.......................1....l72/4 5 3,627,057 12/1971Hartwigetal........................172/126 [54} OUTRIGGER BOOM FOREARTHWORKING VEHICLES [75] Inventor: Gene B. Easterling, Decatur, Ill.

[73] Caterpillar Tractor Co.

Nov. 22, 1971 21 Appl. No.: 201,087

Primary Examiner-Robert E. Pulfrey Assistant Examiner-Stephen C.Pellegrino Atr0rneyJoseph L. Strabala Peoria, 111.

Assignee:

Filed:

[52] US. Cl. ......................l72/4.5, l72/4.5, 172/26,

[51] Int. Cl. 63/111,

Field of Search.......................

pivoted on the inboard end of the cradle so that the boom assembly canbe aligned with the cradle and tightly clamped therein when in use torigidly couple them so a universally adjustable mounting device at [56]References cued the outer end of the boom assembly can attach and UNITEDSTATES PATENTS orient sensing transducers whereby external referencescan be utilized for control system reference t a h w e m 0 S w S m n mau 1w m m g m .m cm Cr. me D 4 r m m .l mm m u C SV 5 m W t om. me m n mem 8 V XX w sj 44 M NU J HH Hickey 4/1969lverson.............................

rS .mm we EM 560 456 999 111 90 1 6556 6344 13 4725 8623 3 .9 2223Patented June 5, 1973 3,736,987

2 Sheets-Sheet 1 INVENTOR GENE B. EASTERLING W41 21,4; 7414 wi-qw'ATTORNEYS Patented June 5, 1973 2 Sheets-She at 2 INVEN'R )R GENE B.EASTERL ING OUTRIGGER BOOM FOR EARTIIWORKING VEHICLES BACKGROUND OF THEINVENTION Specifications in earthworking grading and finishingoperations often require the finished grade and slope to be withinone-eighth of an inch of those prescribed. In the past only highlyskilled operators of earthworking machines, such as motor graders, couldfinish grades and slopes to such exacting parameters. Currently gradingmachines are now in use which automatically control their earthworkingimplements to achieve such exacting standards by sensing variousexternal references to serve as primary inputs into the control systemin order to achieve the necessary control information. A blade controlsystem for a motor grader described in US. Pat. No. 3,486,564 issued toPage et al. is amply illustrative of automatic blade control systemsused for motor graders and some of the types of external references usedfor such controls are described in US. Pat. No. 3,495,663, issued toScholl et a1. Such references are often wires strung along the workcourse of the vehicle that are accurately placed by surveying, oralternatively they may be finished surfaces contiguous to the workcourse on which the grading operations are being accomplished.

As can be appreciated, the cost of providing some of these temporaryreferences, such as the surveyed wires strung along a work course, isexpensive. If an adjacent finished or graded surface having knownspecification can be utilized as a reference, further economies can beexperienced with automatic blade control and like systems. However,because it is conventional to attach the sensing transducers directly onthe end of the grader moldboard or similar earthworking implement, suchas shown in the above-mentioned patents, it usually necessitates thatthe wire be strung extremely close to the existing work course and thatno obstructions exist between the end of the moldboard and the externalreference so the sensing elements of the transducers can track thereference without interference. Of course, with a wire reference strungclose to the work course the operator of the vehicle must be careful toavoid disrupting the surveyed wire and also must keep the end of themoldboard extremely close to the wire so that the sensing elements canobtain a reference therefrom thereby restricting its positioning.

Thus, a principal object of the instant invention is to increase theflexibility of an earthmoving vehicle by giving it the capability to useexternal references somewhat remote of the vehicle by providing a fullyadjustable outrigger boom to mount sensing transducers in a cantileveredmanner from the vehicle so that somewhat remote external references canbe utilized by earthworking vehicles having automatic control systems orreference reading systems for achieving exacting standards in gradingand finishing operations.

It is also an object of this invention to provide an outrigger boomwhich is a sufficiently stable support when mounting sensing transducersin a cantilevered arrangement so that vibrations, deflections and ordistor tions in the boom will not introduce substantial error into thecondition sensed by the transducer and also a boom which also can befolded to a stowed position, when not in use, thereby increasing vehicleflexibility.

SUMMARY OF THE INVENTION To achieve the above objects and advantages anadjustable outrigger boom for an earthmoving vehicle supporting sensingtransducers in a cantilevered arrangement from such vehicles includes anelongated angled support cradle fixedly attached to the vehicle or itsearthworking implement and mounted so that one of its ends projectstherefrom, with the support cradle having a clevis connection at itsinner end, a telescoping boom assembly having an outer tubular memberwith one end pivoted in the clevis connection so it can be swung intoparallel alignment with the support cradle with the boom also having atleast one inner tubular member telescoped within the outer tubularmember and selectively lockable therewith against relative movement anda clamp engageable with the outer end of the support cradle and operableto wedge the outer tubular member into the support cradle for maximumrigidity of the boom when in use which also allows the boom assembly tobe conveniently released from the cradle and stowed in a protectedlocation when not in use. At the end of the boom assembly is a universalattaching device through which various sensing transducers mountedthereon can be selectively oriented and locked in such orientations sotheir sensing elements will track on external references, such asfinished road surfaces, surveyed wires and the like. Obviously a numberof different sensing elements, such as wands or soft pneumatic tires,may be utilized to operate the transducers.

DESCRIPTION OF THE DRAWINGS FIG. I is a perspective of a motor graderhaving the outrigger boom mounted thereon in its operating position witha transducer mounted on its outer end;

FIG. 2 is a cross section of the outer end of the boom and supportcradle, illustrating how the boom is locked in the cradle with a clampfor maximum boom rigidity;

FIG. 3 is a broken-away partial section of the universal attaching unitat the distal end of the boom assembly; and

FIG. 4 is a broken-away sectional view along line IV-IV of FIG. 1showing additional detail of an extension unit for remote positioning ofa sensing transducer.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to FIG. I, a motorgrader 10 is illustrated having a drawbar 1 l universally connected inits bolster l2 and supported from the arched frame 13, extendingrearwardly from the bolster, through lift arms 14 journalled on theframe and hydraulic jacks l5 linking the ends of the lift arms to thedrawbar frame. In turn the bottom of the bolster is supported onsteerable front wheels 16 and the rear portion of the arched frame isattached to the tractor unit 17 of the grader that is supported by rearwheels 18. In the above manner the drawbar is suspended under the archedframe so it can be adjusted by actuation of either the jacks or the liftarms for full maneuverability of its moldboard.

Mounted underneath the drawbar I1 is a circle 19 which is securedthereto in a conventional manner using C-shaped brackets (not shown)attached to the drawbar which support the circle therebeneath forrotation, so that its inner teeth 20 can be engaged by drive unit 21 torotate the circle about its center. Two spaced apart downwardly orientedshanks 22 support the moldboard 23 from the circle in a conventionalmanner on slide shoe brackets so that the moldboard can be side shiftedthrough operation of jack 2 and so its top edge can be oscillated foreand aft to adjust the pitch of its cutting edge.

Thus, the moldboard can be conveniently controlled for cutting andgrading operations and is usually stabilized by a drag link mountedangularly from the drawbar to the grader frame so that the moldboard orblade positions will be precisely maintained.

By connecting valves operating the hydraulic jacks to an automatic bladecontrol system, such as the blade control systems described in theafore-mentioned US. Pat. Nos. 3,486,564 and 3,495,663, the moldboard canbe continuously adjusted with regard to both slope and grade to performprecise and accurate finish grading operations. As can be seen in thedisclosure of the afore-mentioned patents, the sensing transducers forgrade for grade and/or slope control are mounted at the ends of themoldboard in order to sense the position of a surveyed wire referencestrung along the work course or other external reference adjacentthereto. Thus, when the moldboard can be operated closely adjacent tosuch. external references so they can be reached by wands or the likeoperating the transducers on the end of the moldboards, the automaticblade control system described above, will operate satisfactorily.However, if the external reference is located some distance or remotefrom the work course or if the moldboard must be manipulated in a mannerbecause of existing conditions, whereby it cannot be positioned closelyadjacent to such external references, such automatic blade controlcannot be effectively utilized. Thus, the instant invention is designedto increase the flexibility of automatic blade control systems in motorgrader and like applications in the earthmoving field by providingcantilevered remote mounting for sensing transducers.

An outrigger boom 30, according to this invention, is used to mount thesensing transducers closely adjacent to remote external referenceswhereby additional flexibility can be obtained with automatic bladecontrols in motor graders and the like. Universally adjustable, thisboom includes an elongated angle support cradle 31 which is welded orbolted directly to the drawbar 11 so that one of its ends projectsoutwardly from the drawbar as shown in FIG. 1, and in this embodiment,the support cradle is attached directly to the movable earthworkingmoldboard of the motor grader which is accomplishing the cutting andfinishing operations through the drawbar connection. At the inboard endof this cradle is a clevis connection and an angle support cradle may belocated on both sides of the drawbar so that the outrigger boom can besimply changed to the opposite side of the grader if desired, and eachcradle has a forwardly oriented strut 33 connecting its outboard end toa central portion of the drawbar forward of the support cradle toincrease its stability.

The main boom assembly 34 consists of three telescoped, cylindricaltubes with the outer tube 35 having its inboard end fitted into theclevis connection and secured therein with bolt 36 so that this portionof boom assembly can be cradled in the angled support cradle 31 or swungforwardly so that it parallels the drawbar frame where it can be securedon a bracket 37 when not in use, thereby avoiding interference withother types of grader operations. When the outer tube is cradlecl in theangled support cradle, an angle clamp 38 having ears 38a engaging theouter surfaces of the cradle and having a wedging bolt 38b threaded inits reinforced corner 38c so it bisects the apex of this corner, can beassembled therewith so that its wedging bolt will tighten against thesurface of the outer tube, wedging it into the corner of the supportcradle, thereby achieving a maximum rigidity between the outer tube andthe cradle as can best be seen in FIG. 2. This arrangement allows theouter tube to be fixedly secured against all movements and distortionswith respect to the drawbar when clamped in the support cradle and yetallows it to be simply released and swung forward through the pivotformed by the clevis connection when it is desired to stow theboornassembly when it is not in use.

Telescoped within the outer tube 35 is an intermediate tube 39 thatsnuggly fits therein and can be selectively locked in any extendedposition with a lock bolt 40 threaded radially into the outer tube toabut against the surface of this intermediate tube when tightened.Telescoped within the intermediate tube is the outboard tube 41 of theboom assembly which can be locked against relative movement with theintermediate tube with a lock bolt 42, in the same manner as theintermediate tube is locked with the outer tube in the inboard portionof the boom assembly. Through this arrangement a telescoping boomassembly is provided which, when clamped into the cradle with itsseveral tubes locked against movement, provides a relatively stable boomunit having little distortion and deflection between its mounting on thedrawbar l1 and its distal end. Obviously the cylindrical structure ofthe telescop ing parts of the boom provide a relatively stablearrangement against deflection. However, to some extent, as the boom isextended, deflection thereof may increase slightly.

At the distal end of the outboard tube 41 is a ball 43 that fits into asocket 44 which can be tightened with bolts 440 (See FIG. 3) to lock theball and socket together as an integral unit once an adjustment of thesocket has been made relative to the boom assembly. On the socket is anattachment bracket 45 having an angle pad 45a on which an angled clamp46, identical to angle clamp 38 but smaller in size, is employed totightly secure an extension post 47 therein with its wedging bolt 46a.Alternatively, the transducer can be mounted in this bracket. The postforms an extension from the universal adjusting device formed by theball and socket connection at the distal end of the boom whereby sensingtransducers can be further displaced relative to the end of the linearboom in order to conveniently reach external references above or belowthe boom assembly.

A cross clamp 48, best shown in FIG. 4, includes two angle pads 48a and48b transversely oriented with respect to one another and respectivelycooperating with angle clamps 49 and 50, which are similar to angleclamps 38 and 46, to lock the cross clamp to post 47 and to an arm 51 ofa transducer unit 52 secured to the bottom of the post with the crossclamp. Instead of the lock bolts used for angle clamps 38 and 46, angleclamps 49 and 50 use threaded lugs 49b and 50b that function like thelock bolts but which can be tightened and loosened by hand due to theirL-shaped configuration.

With all of the aforesaid adjusting devices secured tightly so the boomis locked rigidly in the cradle and all joints between the cradle andthe transducer units locked against movement, the boom assembly willhave very little deflection or distortion when sensing externalreferences with transducers mounted on the end of the boom assembly orthe extension formed by post 47, since very little boom load isexperienced during such sensing operation. Further, it can beappreciated that the orientation of the transducer unit can beuniversally varied by virtue of the afore-described adjustments andconnections, thereby enabling the transducer unit to reach, withinreason, any external reference within a limited area along the graderwork course.

For purposes of illustration a wheel-type transducer unit 52 is shown inthe drawings and a transducer unit of this type is more detailed in theafore-mentioned U.S. Pat. No. 3,495,663, issued to Scholl et al. In sucha unit yoke 53 is swingably connected to its mounting arm 51 so that thesoft tire 54, supported in fork 55, can track on a previously finishedor graded surface for purposes of establishing external reference bywhich an automatic grader control can be operated. In the transducerdescribed, the fork is pivoted in the yoke so that it will turn thewiper arm of a potentiometer (not shown) in order that verticalmovements of the fork will generate a signal proportional to suchmovement of the tire-on the external reference surface, therebyproviding the necessary output signal information.

The output signal from the potentiometer is conveyed from the transducervia cable 56 strung on the boom to the control system. It should beappreciated that instead of a fork 55, a wand could be pivoted in theyoke and track on a wire or similar surface to provide the necessaryoutput signal information.

What is claimed is:

1. In an earthworking vehicle having a movable earthworking elementanoutrigger boom for supporting sensing transducers remote of thevehicle in a cantilevered arrangement comprising:

an elongated support cradle fixedly attached to said earthworkingelement with its outer end projecting therefrom, said support cradlehaving a clevis connection at its inboard end and fixedly joined to saidearthworking element to move therewith;

a telescoping boom assembly having an outer tubular member and at leastone inner tubular member snuggly telescoped in said outer tubular memberwith locking means selectively securing said tubular members againstrelative movement, said outer tubular member having its inboard endpivoted in said clevis connections;

clamping means engageable with said support cradle and operable to wedgesaid outer tubular member into said support cradle when the former isaligned with the latter to rigidly lock them together as a unit; and

universal adjusting means mounted at the distal end of said boomassembly operable to selectively orient sensing transducers mountedthereon at loca tions remote from said earthworking element whereby saidsensing transducers may accurately register deviations between saidearthworking element and an external reference on which said sensingtransducers are tracking.

2. The outrigger boom described in claim 1 wherein the movableearthworking element is a moldboard supported from a drawbar and thevehicle is a motor grader.

3. The outrigger boom described in claim 2 wherein the angled elongatedsupport cradle is formed from angle iron and includes a brace memberconnecting its outer end to the drawbar to increase the end stability ofsaid support cradle.

4. The outrigger boom described in claim 1 wherein the universaladjusting means mounted at the end of the boom assembly includes alockable ball and socket unit which allows universal orientation ofsensing transducers mounted therein.

5. The outrigger boom described in claim 4 wherein the universaladjusting means includes an extension means for mounting sensingtransducers remote thereof, whereby said sensing transducers can belocated off the axis of the boom assembly to track references above andbelow said axis.

1. In an earthworking vehicle having a movable earthworking element an outrigger boom for supporting sensing transducers remote of the vehicle in a cantilevered arrangement comprising: an elongated support cradle fixedly attached to said earthworking element with its outer end projecting therefrom, said support cradle having a clevis connection at its inboard end and fixedly joined to said earthworking element to move therewith; a telescoping boom assembly having an outer tubular member and at least one inner tubular member snuggly telescoped in said outer tubular member with locking means selectively securing said tubular members against relative movement, said outer tubular member having its inboard end pivoted in said clevis connections; clamping means engageable with said support cradle and operable to wedge said outer tubular member into said support cradle when the former is aligned with the latter to rigidly lock them together as a unit; and universal adjusting means mounted at the distal end of said boom assembly operable to selectively orient sensing transducers mounted thereon at locations remote from said earthworking element whereby said sensing transducers may accurately register deviations between said earthworking element and an external reference on which said sensing transducers are tracking.
 2. The outrigger boom described in claim 1 wherein the movable earthworking element is a moldboard supported from a drawbar and the vehicle is a motor grader.
 3. The outrigger boom described in claim 2 wherein the angled elongated support cradle is formed from angle iron and includes a brace member connecting its outer end to the drawbar to increase the end stability of said support cradle.
 4. The outrigger boom described in claim 1 wherein the universal adjusting means mounted at the end of the boom assembly includes a lockable ball and socket unit which allows universal orientation of sensing transducers mounted therein.
 5. The outrigger boom described in claim 4 wherein the universal adjusting means includes an extension means for mounting sensing transducers remote thereof, whereby said sensing transducers can be located off the axis of the boom assembly to track references above and below said axis. 